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Another same thing only different, again

I was thinking more about what you had mentioned concerning low speed thrust. This machine uses the York 4 piece coupling with 3 bolts 120* apart and once that unit is tightened down there can't be any movement fore and aft to stress the seal. Excuse me as I'm thinking online. One possibility does exist though. We haven't checked the motor for magnetic center, if it draws aft it adds pressure to the seal and if it draws forward it takes spring pressure off the seal. I worked on another OT that had this big (10") rubber flex coupling with an iron internal and external hub. Even though it was flexible you had to have it perfectly aligned or it wouldn't go together. If you put a strobe light on it you could watch it flex during start-up. Soft starter 45 seconds to come up to speed. I think I may have something else to look at.-GEO

Here again, my familiarity is solely with early 90's to 2000 YTs, and even with the coupling bolted up, you can set up the dial indicator and bar the shaft in and out. This is the coupling with the layers of flexible spring steel between both ends of the central "spool" piece, and the shaft flanges.

I was thinking more about what you had mentioned concerning low speed thrust. This machine uses the York 4 piece coupling with 3 bolts 120* apart and once that unit is tightened down there can't be any movement fore and aft to stress the seal. Excuse me as I'm thinking online. One possibility does exist though. We haven't checked the motor for magnetic center, if it draws aft it adds pressure to the seal and if it draws forward it takes spring pressure off the seal. I worked on another OT that had this big (10") rubber flex coupling with an iron internal and external hub. Even though it was flexible you had to have it perfectly aligned or it wouldn't go together. If you put a strobe light on it you could watch it flex during start-up. Soft starter 45 seconds to come up to speed. I think I may have something else to look at.-GEO

The few OT's i've played with had ball bearing motors. I don't believe you'll find much movement. I do have a couple of sleeve bearing motors where you can visually see the motor find magnetic center, with it uncoupled, of course.They'll move 1/2'' from either thrust/counterthrust position to center. Kind of a cool sight the first couple of times.

In think we may have found out something

Klove, excuse me as it has been a while since I updated this thread. Actually I have gone so far as to start another post. There was NO low speed thrust. No axial shaft movement. The high speed had min .010". We pulled the compressor out of the scroll housing. After separating all the oil plates on the impeller side the low speed oil pump has burnt oil through it. There is more information on my other post York oil seal, part deux, thanks again-GEO

On the YT's I have under my care, I run them at about a half PSI positive. That gives more oil flow through the seal cavity, and keeps the seal cooler, but still a full cavity. Get the low speed thrust specs for your unit and check to see that you're within specs there, too.

Well, I'm not familiar with that particular machine, but on the YTs its more like a bearing oil run off that flows through the seal cavity, and the regulator is like a drain regulator. You might want to take it apart and see that it isn't hanging up, or maybe even replace it if it shows any sign of wear. Or be cheap with a piece of crocus cloth and polish it up. The last bellows seal I replaced on an R-123 machine showed signs of overheating. It was set for about a PSIG and a half at 60HZ, Also have a couple 11 machines that haven't seen much surging and have seals in then that are 15 years old. One of my own harebrained theories is that the 123 hardens the o-rings on the shaft and binds the piece that has to move on the shaft with the older seals.

Another option

If you don't want to play the washer game, York has an adjustable regulator stem style available for setting seal pressure and jet pump pressure on LTD compressors and HT units makes it a whole lot easier.-GEO

If you don't want to play the washer game, York has an adjustable regulator stem style available for setting seal pressure and jet pump pressure on LTD compressors and HT units makes it a whole lot easier.-GEO

Interesting, what seal pressure do york recommend when you buy this valve. You got any info on these

Adjustable regulator

All it is, is an adjustable regulator that screws in the same opening as the original hex fitting. You still use the original valve stem and spring, they fit right inside the regulator. It is a whole lot easier to adjust a stem then to have to operate the pump find the pressure then add or take away washers while air gets sucked into the system. Don't have the actual York part #. There is no change of pressure setting for seal relief, it is still the same 2 #'s under full load with 16" hg evaporator pressure.-GEO

Last edited by ga1279; 10-23-2010 at 01:11 PM.
Reason: OOOPS I forgot something

Once in a while everything falls into place and I am able to move forward, most of the time it just falls all over the place and I can't go anywhere-GEO